Rolling mill and lubrication method and means therefor



Sept. 4, 1951 T. SENDZIMIR ET AL 2,566,679

ROLLING MILL AND LUBRICATION METHOD AND MEANS THEREFOR 3 Sheets-Sheet 1 Filed Feb. 25, 1943 ------4i'/IIIIIIIII p 1951 "r. SENDZIMIR ET AL 2,566,679

ROLLING MILL AND LUBRICATION METHOD AND MEANS THEREFOR Filed Feb. 25, 1945 3 1-3heets--Shee*- 2 Sept. 4, 1951 T- SENDZIMIR ET AL ROLLING MILL AND LUBRICATION METHOD AND MEANS THEREFOR Filed Feb. 25, 1943 FIG. l9

III I xww FIG

3 Sheets-Sheet 5 6 gala:

9 1 mu Y Patented Sept. 4., 1951 UNITED j srA'r-Es PATENT OFFICE ROLLING ItIILL AND LUBRICATION METHOD AND MEANS THEREFOR Tadeusz Sendzimir and John a. Eckert Middletown, Ohio, assignors to Armzen Company, Middletown, Ohio, a corporation of Delaware Application February 25,1943, Serial No. 477,087

27 Claims.

The field of utility of our invention lies in the operation and construction of rolling mills of a type in. which the roll-separating forces are transmitted in a uniform manner to rigid beams extending in the direction of the axis of the working rolls. An example of such a mill is the strip millemploying small diameter work rolls ultimately backed at closely spaced intervals by narrow and relatively small-size bearing rings (casters), with supports between the latter so that the rolling pressure, inch by inch across the width of the strip is delivered from the spot on the work rolls where it is generated to the corresponding spot on the solid housing beam, as set .forth in several patents to applicant, Sendzimir, of which No. 2,169,711 is an example. The high degree of rigidity and precision of this mill is primarily due to the backing of the work rolls by a very rigid housing and to a diminution of the roll-separating force because of the small diameter of the work rolls.

It has been understood that this type of mill lends itself to the maintenance of the operating elements in a bath of lubricant, and such mills are being so operated. The lubricant on the mill is usually either an oil, straight or compounded, or an emulsion of a suitable grade of lubricant in water. For temperature control purposes, the lubricant is brought to the desired temperature and circulated through the housing with intermediate filtering. The rate of circulation will be fairly rapid, depending upon the cooling quality of the lubricant. It will be understood that the precision of the work done by the mill will be afiected by the maintenance of fixed rather than variable temperature conditions, and by the maintenance of uniform temperature conditions along the length of the working rolls and other operating elements.

The procedure has been to deliver the oil through openings in the housing, near the top of the upper backing bearing rings (casters) and to let it out through similar openings near the bottom casters. A certain quantity of lubricant. of course, escaped through the restricted passages, sealing rolls, wipers, etc., in the slots in the mill housing where the strip enters and leaves the mill; but this quantity was minor and was minimized as much as possible by sealing means in the slots.

This method has certain disadvantages the most important of which is that the dirt and metallic particles, which are unavoidable in regular operation, even on a cleanest strip obtainable, have access to the bearings and sometimes cause their premature failure. Another disadvantage is thatthe delivery of the coolant-lubricant is not the same, as regard the various portions of the rolls and backing elements. The cleaned and cooled oil first gets into the top portion of the mill, and is heated up before it reaches the bottom portion. In the bottom portion of the mill, it enters largely at or near. the ends of the work rolls, beyond the edges of the strip, so that the bottom bearings at the middle portion of the. strip are flushed by the hottest and most contaminated lubricant. This condition is further aggravated by the fact that the backing rings tend to become magnetic after they have been in use for a time. Then they begin to attract little steel particles which thus become rather difilcult to flush away.

Thus, there is in this procedure essentiallyno way of controlling the flow of lubricant through the housing. From the standpoint of lubrication, some bearings are lubricated by clean, fresh voil, while others tend to have flushed into them sludge and particle arising elsewhere in the system. From the standpoint of cooling or other temperature control, the operation was imperfect because the coolant could not be delivered to all mill parts under equal temperature conditions. The fluid had-to pass from the upper part of the mill housing into the lower around the edges of the strip. Thus, theflow was unduly diminished at certain places and accelerated at others. Dead spots were likely to form. From the standpoint of using the fluid to flush sludge and particles out of the mill. the operation was thus imperfect. Hence, at the completion of rolling of each coil, all the lubricant contained in the housing was usually let out in order to flush the rolls, caster and their bearings, and to carry away the slugs and small metal'particles that might have lodged themselves in various place in the mill; Such impurities are chiefly near the bottom bearing rings, in the bores of the housing; and simplydraining all the lubricant from the housing was frequently not sumcient to remove them. The present invention solves this problem in a radical way and gives, in addition to it, a number of important operational advantages.- This constitutes one of. the principal objects of our invention.

In its broadest aspect, our invention contemplates the introduction of the lubricant to the operating instrumentalities simultaneously and in a uniform manner on both sides of the strip being rolled, and its removal from the housin substantially at the level of the strip. It may,

indeed, be wholly removed from the housing by flow through the housing slots in the plane of the strip. Thus, the lubrication of the upper and lower parts of the operating instrumentalities in the mill housing becomes independent and con-' 5 trollable, with the strip acting as a diaphragm between.

According to one aspect of the invention, the lubricant is delivered under a somewhat higher pressure, (say; a couple of pounds per square inoh),'flrst to the inside of the bearing rings, in substantially equal amounts to each bearing ring, and in a quantity at least sufficient adsquately to carry away the heat generated. The lubricant leaves those bearings through restricted passages, fixed clearances and the like between bearing rings, so dimensioned as to maintain a pressure gradient between the space inside of the bearing rings and the interior of the housing outside these bearing rings. This pressure gradient, coupled with the centrifugal force caused by rotation of the bearing rings, causes the lubricant to flow steadily and at a rapid rate through these restricted passages, and into the general oil bath in the housing. In this way, the bearings are positively protected from the ingress of any dirt and small metallic particles from the general bath. Particles cannot possibly enter through these restricted passages against the rapid flow of the lubricant.

In the light of our teachings, several methods are available for delivering the lubricant to the bearings of said casters, but we have developed one that offers substantial savings in the assembly and maintenance of the mill. The spaced supports or bearing members" which are located in the inner machined surfaces of the housing, and which support, at frequent intervals, the shafts carrying the casters were formerly made as individual supports, (see 50, Fig. 8, m Patent 2,169,711). According to this phase of the present invention, they are connected in groups, depending upon the size of the mill and other considerations. Usually all supports belonging to one shaft can be joined as one piece. In some instances, the supports of two or more shafts, or even of all shafts belonging to one work roll, can be thus executed as one single part. This improvement permits us to establish the lubricant connections more efficiently, in that suitable oil passages provided in the housing are arranged so as to face similar openings and channels on the outside periphery of the one-piece support or "cradle, through which the lubricant is delivered into the bearing space. The respective component of the roll-separating force presses the cradles firmly into the bore of the housing so that, with this connection, no couplings, seals or gaskets are necessary and, moreover, should so there be any leakage'of the lubricant at this interface, the lubricant could only get into the in-. terior of the mill; and this is not harmful.

An equally important improvement derived from the joining up of the individual supports in- 05 to one cradle, for each bore in the housing, or even combined cradles for two or more bores in the housing jointly, resides in the fact that inspection, cleaning and maintenance of the mill is greatly simplified and facilitated. Such cradle, together with its shaft and the plurality of hearing rings (casters), is arranged as a complete sub-assembly and can be quickly mounted into or withdrawn from the mill as a complete unit. in contra-distinction to the mounting of individual 16 4 supports, than their shafts with hearing rings, as heretofore.

It is preferable to employ saw-tooth wedges on similar elements to clamp these cradles securely in the bores of the mill housing in such manner that these clamping elements can be tightened or released from one end of the housing, In this manner, having on hand an interchangeable second set of complete cradle units, a mediumslzed mill, (for example, one to roll a 50-inch wide strip), can be opened and all the bearings, rolls and intermediate rolls replaced and production started again in between half'an hour and one hour, depending on the ability of the men, as against eight or ten hours, with the previous practice. The bearing rings and parts which were taken out can be cleaned and inspected later, usually by the roll grinder, at his convenience, and then reassembled for future use.

As indicated, a fluid circulated through the mill may have three primary functions, viz.: (1) lubrication, (2) temperature control, and (3) cleaning, or the flushing away of foreign bodies.

Considering lubrication alone, there is the lubrication of working parts of the mill, and there is the lubrication or the surfaces Of the piece against therolls. In many instances, a single lubricant may be employed for both purposes. In other instances, one lubricant may be required for bearings and similar parts, and a dinerent lubricant for the rolling operation. Ob ects of our invention have to do with the solution of problems presented by these considerations.

In some instances, lubricants of dissimilar nature may be mixed within the housing and afterward separated by suitable means; but in other instances this is not possible, and means must be provided for the segregation of lubricants within the mill. Objects of our invention have to do with the solution of problems presented by these considerations. As to temperature control, objects of our invention have to do with the control of the flow of fluid through all parts of the housing, the maintenance of uniform flow, the prevention of dead spots, and the like.

Similar considerations in the matter of flushing give rise to objects of our invention connected with flow control with, however, particular attention here to the acceleration of flow or the formation of jets at particular positions where the removal of sludge or particles is imperative, or at particular positions where sludge or parti-- cles are likely otherwise to accumulate. I These and other objects of our invention, which will he set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, we accomplish by that construction and arrangement of parts of which we shall now described certain exemplary embodiments. Reference is made to the accompanying drawings, wherein:

Figure 1 is a sectional view of an exemplary rolling mill, showing an arrangement for lubricant circulation in accordance with the invention, and illustrating also the use of joined or unitary cradles.

Figures 2, 3, 4, 5, 6 and '7 show casters and their mountings in various forms, together with modes of delivering lubricant to the caster bearings and supports, or modes of delivering coolant fluid as distinguished from lubricant to parts likely to become heated.

Figure 8 is a sectional view of a type of structure for forming a fluid jet for flushing purposes.

Figure 9 is a sectional view of another structure for the same purpose.

Figure 10 is a partial sectional view taken along the lines :e-m of Figure 8.

Figures 11 and 12 are elevational views of mills in which the housings are sectional in character, so that the mills may more readily be opened for cleaning, repair and replacement.

Figures 13 and 14 are illustrative of certain means for controlling the flow of coolant or lubricant, and certain means for lubricant or coolant segregation.

Figure 15 is a partial plan view showing a particular type of caster arrangement employed in the mills of Figures 1, 13 and 14.

Figure 16 is a sectional view of a type of mill employing oil-film bearings.

Figure 17 is a partial plan view of a reciprocating arrangement therein, Figure 16 being related to Figure 17 as indicated by the section line 11-11 in the latter figure.

Figures 18, 19 and 20 show in section modified types of mill to which my invention applies.

Figure 21 shows yet another arrangement of operating elements in a mill.

Figures 22 and 23 show bearing arrangements for the caster rolls arranged for segregation of lubricant.

One of the broader aspects of our invention is illustrated in Figure 21. The mill beams are shown at l and 2, extending in the direction of the length of the rolls. These beams will, of course, be connected by vertical housing members at or near the ends of the rolls. The strip passing through the mill is indicated at 3, and the small working rolls are indicated at 4 and 5. Through the intermediary of one or more sets of rolls 6 or I, the working rolls are supported by means of casters 8, 9 or I0, I I. The casters, in turn, are mounted upon shafts such as the shaft 12. Intermediate the casters, the shaft I2 is supported from the beam 1 by means of cradles 13. The screw down of the mill is arranged for, either by making thoseportions of the shaft i2 which are mounted in the cradles i3 eccentric and varying the position of the shaft by rotation, or the cradles themselves may be eccentrically mounted in machined sockets in the beams. In the par-. ticular mill shown, the arrangement is such that the greater part of the roll-separating force is .borne by the outer casters 8 or ill. The intermediate casters 9 or II, bearing less of this thrust, may be made smaller with certain advantages, among which is the gaining of depth in the beams for a given over-all height of the mill.

Considering the matter of lubrication and cooling, we provide in our beams certain passageways I4 and I5, and these are shown connected with the bearing structures by means of passageways as at I! or II. Various modes of delivering the lubricant to and circulating it in the bearings will hereinafter be described. However, the lubricant in Figure 21 first passes through the bearings of the several casters and the bearings of the supporting shafts, if desired, and then joins a body of lubricant filling the entire interior of the mill housing. This bath or body is in continuous motion because of the action of lubricant circulating means .outside the mill (not shown); but it will be noted that the lubricant enters the mill both above and below the strip through delivery passageways l4 and i5, and in passing through the mill housing, it first moves toward the strip 3 from both sides, and then moves outwardly along the strip both above and beneath it. Sealing rolls l8 have been shown at both ends of the mill slot or throat i9. They are useful in removing excess oil from the surfaces of the strip as delivered by the mill, as well as in maintaining some pressure of lubricant or coolant within the mill. But the egress of coolant or lubricant from the mill is through the throats l9, and it may be drained away at the sides of these throats and of! the edges of the strip. Special passageways may be provided for this if desired. Or the lubricant may be drained out through the seals, or again, th seals may serve merely as wipers for the strip and be located away from the ends of the throats, allowing frec egress of lubricant.

Since the lubricant is delivered substantially uniformly and in equal increments along the length of the caster bearings or the shafts l2, the flow of lubricant is thus controlled in such manner that it is uniform and even as respects all parts of the operating instrumentalities and of the strip being rolled. There are no dead pockets, nor is contaminated lubricant delivered from one bearing to another. The strip 3 acts as a diaphragm between the two parts of the operating mechanism which are each individually lubricated. Means on the mill housings usually effect a seal at or near the ends of the working and intermediate rolls; but it is not always necessary that seals be efiected at these points. The lubricant simultaneously, but separately, enters both the upper and lower parts of the mill-housing, flows toward the work piece, and is removed at the level of the work piece. Hence, there is little or no tendency for lubricant on one side of the work piece to mingle with lubricant on the other within the mill housing itself.

Figure 21 also illustrates another means for control in flushing, but this will be described later.

supported at spaced intervals by supports form-.

ing part of cradles 23. A cradle 24 is a double cradle and has supports for both shafts carrying the casters 2|. The type of mill shown is again one in which the arrangement is such that the greater part of the thrust forces is sustained by the two outer sets of casters 20. The inner sets of casters 2| are made narrower and are intermeshed (as illustrated in Figure 15). This arrangement possesses certain geometrical advantages, and also permits us to apply certain new screw-down or mill-release techniques and constructions, as set forth in a companion case copending herewith.

In Figures 1 to 6, the coolant or lubricant is delivered through passages (marked IS in Figure 1) in the housing beams, and from there through passages 25 to grooves 26 in the cradles. These grooves may be made wide enough to permit such rotation or rocking of the cradles for mill adjustment as may be required by the particular mill design. Further passageways 21 in the cradles themselves are formed to conduct the coolant or lubricant to points of use ordelivery as will hereinafter be described.

Figure 2 shows details of one form of lubricant connections, in longitudinal section, of the outer, non-staggered casters 20, and Figure 3 shows a similar section for the inner staggered casters 2|. The coolant-lubricant arrives through passages 21 in the cradles, then through cross-holes 28, enters the roller bearings 29 of casters 20. The clearance between support 30 on the cradle and the edges of casters 20 may be small enough to require no special seal; but it is preferable to seal it, and we. have found twomethods of sealing that work satisfactorily, i. e., the one shown in Figure where a sealing ring 3! of a suitable material is pressed against the face of the caster by oil pressure. The outer diameter of the ring 3| has a sliding fit in a corresponding recess in the support 23 to control leakage of lubricant, at this point. Ordinarily, such a sealing ring revolves with the caster. Figure 6 shows a sealing ring 32 which is pressed against the face of the caster 20 by a diaphragm 33 which is mounted in the support 23. To facilitate assembly, such ring and diaphragm may be split.

In the embodiment of Figure 2, the casters 2!] are double in form, and the exit for the coolantlubricant from the bearings 29 into the body of lubricant in the mill work-space is through the passageways or spaces between the casters, as indicated by the small arrows in the figure.

Figure 3 shows needle bearings 34 on the supports 24 for the shaft 35, and these are lubricated through intercommunicating clearances, from bearings 29. In case outside pressure controlled oil-film bearings are used, instead of needle bearings 34, they receive their lubricant under pressure through holes in shaft 35.

In' the embodiment of Figure 3, the coolantlubricant, having passed through the roller bearings 29, may be expelled into the general bath in the mill housing through perforations 36 in the casters themselves. The constructions of Figures 2 and 3 both insure a positive circulation of lubricant through the bearings before permitting it to join the general bath, and result in the expulsion of lubricant to the bath in such a way as to prevent entrance of sludge and metal particles from the bath into the bearings.

According to one phase of the present invention, that portion of the space inside the mill housing which contains the casters and other backing elements i s heremetically separated from that part where the strip passes through, so that the lubricant may flow as above described. This is accomplished, for example, by providing flat tunnel-forming members orremovable separators 31, across the central space of the mill, and around the entering and outgoing portions of the strip, as shown in Figure 1., 'An important part of our invention is the elastic seal of this tunnel against the faces of the work rolls, (which not only rotate, but also are raised and lowered bythe screw-down mechanism). We may employ elastically mounted scraper blades of metal, plastics, or other suitable material, 39a, lightly pressing against the work roll surfaces with their sharp edges. Material of the nature 'of razor blades is excellent material for such scrapers.

Their edges are kept sharpby contact with the rotating work rolls, and they remove from the roll surfaces any metal, dirt and other particles that may have attached themselves, before such particles have reached the contact line with the supporting rolls, through the pressure of which they might otherwise become firmly embedded in the rolls, or cause indentations and other damage.

Full advantage of this aspect of the invention will be realized in connection with our system for the circulation of lubricant, to which end we provide restricted passages for increasing the flushing force of the coolant-lubricant adjacent the work rolls preferably in the form of a plurality of apertures disposed at spaced intervals along the edges of the scrapers, either in such scraper blades or close to them. One such arrangement is illustrated in Figures 8 and 10. The work rolls are shown at 4 and 5; 3 is the strip being rolled, and 38 is either the end of the tunnel-forming members 31, or is a member attached thereto. The scraper blade 39 is elastically mounted on the member 38 by spaced screws 40 and springs 4! so that it pivots on the edge of member 38 at a line of contact which makes the elastic joint hermetic. It is also free to move to accommodate itself to the work roll. Spaced channels 42 are preferably provided in the member 38 which act like nozzles for the lubricant, which flows out through them at considerable velocity, first in a direction parallel to the surface of the blade 38, then impinging against the surface of the roll 5, it flushes the cavity formed between the surface of roll 5 and the strip 3, whereupon it changes direction and at reduced speed moves parallel to the strip 3, away from the work rolls. The nozzle construction is somewhat more clearly shown in Figure 10.

Thi at once solves two important problems: (1) The escape of the lubricant is uniformly distributed along the length of the rolls,-substantially eliminating all flow of lubricant in the direction across the mill with the inherent danger of non-uniform heating of the mill mechanism, and i2) tne continuous flushing away or ah dirt particles caught by the scraper blades, and carrying them out of the mill housing in a steady flow of lubricant towards the restricted passages at the outer end of the slots in the housing is accompiished. Moreover, there is no need for complicated seals at the ends of such scraper blades a spot which is obviously diflicult to seal.

Where necessary, the efiective section of such nozzles 42 can be made adjustable or controllable, and suitable vanes 0r baflie plates can be provided to direct the now of lubricant so as more readily to wash away the dirt picked up by the scraper blades 39.

Instead of scrapers, the present invention makes it possible to use blade-like members 43, (Figure 8) disposed substantially across the width of the strip, but not having contact with the work roll. Such members approach the roll and are so proportioned as to permit lubricant to develop a high velocity at the neck of the jet, or spaced jets, and to flush away all impurities and foreign bodies which might have become separated from the strip during its passage through the working zone. Wherever this arrangement is suflicient, it has the advantage of requiring less skillful and precise mounting than scrapers which, if carelessly mounted, may damage or scratch the rolls. Such an arrangement is generally desirable on the incoming side of the mill where the working rolls are turning toward the work piece 5. Member 43, Figure 8, is preferably linked with the screw-down mechanism so as to provide for the maintenance of an even nozzle section independent of the position of the work rolls. At the ends of such members as 33 and 43, there may be seal or baflle plate 44. While lubricant flow-control members have been illustrated only in connection with work rolls 5 in Figures 8 and 9, it will be understood that lubricant flow-control members will also be provided on the opposite side of strip 3 in connection with roll I.

Flexible mounting of the scraper blades, where the blades are pressed against the roll surface by light spring pressure, is usually suincient to make them follow the roll as it is moved up or down. by thescrew-down means. From Figure -9, it will be clear that the oil pressure within the housing bath exerts a force upon such blades and/or their holders, (if these are flexibly mounted), and that'such pressure must also be overcome by the force o the s rings. This fact makes it possib e to com ine the scraper blade element 39 and the flat nwle element 38-42 intoone. by so proportionin the spring pressure that the scraper blade slightly yields under the oil pressure from the oil bath. thereby lifting the scrap r blade clear of the roll s rface, while the lubricant esca es through a flat noz le fo med etween the blade and the work ro l itself. With lesser oil pressure. the scraper blad comes closer to the roll surface and the section of the nozzle bec mes le s. T e st eam of oil is thus concen-- trat d ri ht at the ed e of the blades where it washes awa im rities while the blade is still close enou h to the roll to catch and remove any larg r sli e s or other, fo ei n bodies. In Fi ure 9. a flat ade 45 mav be inflex b y attached to t e. t nnel member 31 as bv scre s. and mav act itself as a long flat s rin The dotted line shows the posi ion o the blade when it touches the' ork r l 5. and the solid line sho s the normal lifted-up position assumed during operathe edge of blade l5. Such streams of lubricant I penetrate deeper into the bite of the rolls.

Rollers l8, wipers 46, or similar elements, (Figurel) restricting the open passage at the outlet of the housing slot, are installed wherever it is necessary to provide a bath of lubricant for the portion of the strip within the housing slot. In their absence, the muflle-shaped passages at the entrance and exit side of the mill are not usually filled with lubricant, the flow of whch requires considerably less section. With many materials, especially with certain alloy steels, it is important to bring the metal up to a certain predetermined temperature and maintain it at such temperature during the plastic deformation. Certain materials, like, some silicon-bearing steel strips, are distinctly brittle at room temperature and become sufliciently plastic for cold rolling at, for instance, 200 F. There are other materials like stainless steels which, when rolled at such temperatures'as 250 F., show considerably less workhardening than when rolled at lower temperatures. In still other instances, the problem is quite opposite, as for example, when it is necessary to produce the greatest work-hardening with the least cold-reduction. In such instances, the temperature of the lubricant must be kept rather low, close to room temperature. This arrangement with the lubricant escaping through evenlyspaced openings across the width of the strip and evenly flowing. through the muille-shaped passages, within the housing, right up to the passage-restricting rolls which guide the strip, offers a means of maintaining those temperatures conl0 veniently and with suflicient precision, always provided that the lubricant is delivered to the mill in the right condition, quantity, and temperature. As outlined, one of the fundamental principles of this invention is the recognition of the fact that any ilow of lubricant in the direction along the axis of the rolls, 1. e., across the width of the strip is detrimentaLbecause the lubricant picks up heat. The result is uneven heating of the backing elements which impairs the utmost precision and accuracy of'such a mill. The system as outlined herein accomplishes this condition perfectly.

However, with multi-roll backing'systems, this may create another difliculty: the formation of dead pockets between three generants of contacting rolls, as in Figure l. where the lubricant may reach a dangerously high temperature, especially when it is necessary to operate at a high temperature of the lubricant, such as 250 F. or beyond. The present invention solves this problem by providing straight or spiral grooves in one of' the rolls concerned, which grooves both create passages for, and help circulate lubricant through such pockets. Spiral grooves are less expensive to machine and also are better suited actually to propel the lubricant; but to obviate the danger of their creating an axial flow of oil, rightand left-hand spiral grooves may be provided over the whole length of the rolls, or axially,

one=half of the threads may be rightand the other left-hand.

Our teachings set forth above apply to all cases where the coolant-lubricant used for lubricatin the backing bearings on casters can also be used as the lubricant in the roll bite. For some metals this is impossible, or does not conduce to the best.

the caster 20, and filling the bearing with grease.

Cooling, of course, will still be required, and we permit the coolant-lubricant to enter the housing in the way hereinabove described, delivering it to passageways 48, (Figure 4), provided in every other support on the cradle. From there, the lubricant passes successively through passageways 49 into a central perforation 50 in the eccentric shaft 22, leaving through passageways 6| connecting with perforations in the support part 30, when it enters the housing bath. Thus,

the lubricant keeps both the eccentric shaft 22 and the bearings 29 cool so that the grease does not melt. It then lubricates and cools the rest of the backing elements. The caster bearings 3 and 4 are periodically, say weekly, replenished with new grease, as the cradles are exchanged against spareones, for cleaning and inspection.

In still other cases, an independent circulating oil supply for the roller bearings can be both. introduced and withdrawn through the hollow eccentric shafts, without being permitted to mix with the coolant supply in the hollow of the mill housing. This is possible because the quantity of such oil is insignificant compared to the necessary volume and rate of flow of the coolantll lubricant. The coolant will be supplied through. the holes in the housing and cradles as above outlined, but will by-pass the eccentric shafts .ancl roller bearings. In such cases it may be ada separate circulatory system for the caster bearings is shown in Figures 22 and 23. Here, the shaft 22a, on which the casters are mounted, is provided with spaced, longitudinal passageways 52 and 53, which are without communication with each other. This is conveniently accomplished by perforating the shaft longitudinally and mounting a grooved filler 54 in the perforations. Lubricant from the passageway 52 is fed through transverse perforations 55 to the bearings for casters '25, (which bearings are in this instance not shown as roller hearings to indicate that roller bearings constitute no necessary limitation on the general features of this invention) Roller bearings may be used, and the construction of Figures 22 and 23 is equally applicable to them. Seal rings 56 seal off the spaces between the cradle supports and casters, and force the lubricant to return to passageway 53 through transverse passageways 57. At either or both ends of the shaft 22a, suitable inlet and outlet connections are made to passageways 52 and 53.

Thus, the bearing lubricant is both circulated and kept separate from the coolant, which enters, (as hereinbefore described), through passageways 25, 26 and 21, and simply flows around the casters 20 on its way to the general bath in the hollow of the mill housing.

Again in some instances, while the general coolant may be employed as the lubricant for the caster bearings and other mill parts such as intermediate rolls, it is desired to run the strip dry through the working rolls, or it is desirable or necessary to employ as a rolling lubricant some substance which either must not be contaminated by or must not contaminate the general mill coolant. Figures 13 and 14 have to do with solutions of this problem.

Figures 13 and 14 show in cross-section an' other embodiment of a mill, with provision for the above mentioned aspect of the invention. Work roll is shown backed by casters on two shafts, 58 and 59, each having a plurality of spaced casters, 60 or 6|, which contact the work'roll, and which are preferably staggered so as to reduce the apex angle of the triangle between the center lines of 5, 58 and 59. Shafts 58 and 59 are rotatably mounted in cradles 62 and 53, and casters 60 and BI rotate with them, being preferably made in one piece with the shafts. Said shafts may be driven, and they may drive the work rolls by friction, or the work rolls may be themselves driven, or of course, the driving force, as in any of the disclosed embodiments, may be supplied by tension defierence in the strip only.. Cradles 62 and 53 are preferably made eccentric with the axes of the shaft 58 and 59, so that by turning them within the bores of the housing beam 2, a screw-down motion for the work rolls may be obtained. 64 and 65 are split bushings of a suitable bearing material, or they may be suitable anti-friction bearings, like roller or needle bearings.

Again, the casters 60 and 5.]. instead of bei v made solid with shafts 58 and 59 may be roshafts within their bearings, thereby reducing wear and increasing the capacity of the bearings.

In this relatively simple mill, the casters 60 and 6| are likely to mark or cut the work roll which they directly back, owing to the concentration of pressure at the edges of the casters. This is remedied by crowning the casters or at least beveling oiI (relieving) their edges at a slight angle, so as to make the pressure gradually decrease towards the edges.

This prevents marking at the edges. Apart from this, however, there is a little discoloration or duller appearance of the surface of the backed roll, at the surfaces of contact with the casters, whereas the surfaces which face the clearances between spaced or staggered casters do not become so dulled. If the backed roll happens to be a work roll, the strip may have such dull stripes printed on its surface, which is detrimental to quality for certain finishes. It is, therefore, preferable to provide means for relative axial displacement, as between the casters and the backed rolls to obliterate such marks and cause the roll surface to have a uniform degree of polish. The axial oscillations do not need to be more than the width of the clearances between casters, and they may be either continuous or intermittent.

' Under circumstances, even a provision for slightly changing the axial position of the roll or rolls at the end of the operating pass or cycle, or even once per coil will be'suflicient for such purpose. In such a mill, as in the others hereinabove described, lubricant is preferably admitted under pressure through holes 25 spaced over the width of the strip in the housing beam 2, from which it enters through channels (not shown) into bores 21 in the cradles 52 and 63, and into the bearings; and from there, it passes into the general lubricant bath space. In this, or in the other types of mill shown, where it is necessary to segregate the coolant from the working pass of the rolls, the coolant A may be withdrawn through holes 66 or 61 in hollow casings 68 or 69, whence it is removed from the mill for recirculation. The hollow casings 58 or 69 extend across the hollow interior of the mill housing, and take the place of the tunnel-forming members 31 of Figure 1, also supporting wiping blades. We may employ such a blade, for example, as the blade 10 in Figure 13 which, however, has a sufficiently tight contact with the roll 5 as to allow little or no lubricant to escape at this point. It w ll be understood that since the lubricant is withdrawn through holes 56 and casing 68, its pressure can be prevented from building up to the point where it can force its way past blade 10.

Again, we may employ a double-bladed wiper, such as shown at H in Figure 14. The apex portion of this double wiper maybe made arcuate or roll-shaped and mounted as shown in a cylindrical recess or groove in the casing 69. Thus, the whole wiper is permitted to pivot in the groove as the work roll moves up Or down. The lower edge of the double scraper blade removes oil from the roll, so that roll 5 contacts the strip with a dry surface, whfle, when the rotation is aseao're reversed, the upper edge of same blade removes metal particles and impurities from the roll surface. The casings 68 or 69 are made easily removable as they may need frequent cleaning.

The teachings above indicate both how the caster and caster-shaft bearing lubricant can be isolated from the general coolant bath, and how the general coolant bath may be isolated from the roll pass. In the light of these teachings, it will be clear how they may be combined in any given mill to isolate any of the systems from the others or all the systems from each other. While the U. S. patent above referred to indicates the use of a housing either made all of one piece, or of several pieces of metal so joined together that the bending resistance of the vertical column portions helps to reduce the deflection of the horizontal beams under the load of roll pressure by such a constrained junction, the present invention also applies to housings with little or no constraint at the junction between the beams and the column portions. The measure ofapplying a constrained joint at this point has as its main object economy in weight ofthe housing, for a given tolerated deflection of the beam. But in certain cases, weight of the housing is no objection, because the more rigid the beam, the less gain can be obtained by making thehousing all in one p ece. r

With, the present invention, where the lubricating system for the top work roll and its backing elements is virtually autonomous from the one for the bottom roll, and where the convenience of providing, adjusting and maintaining. individual seals for the two systems is a. major problem, certain advantages can be obtained by pro viding a mill housing consisting of two pieces, each to include the beam portion corresponding to one of the work rolls.

Figure 11 shows a housing of this type, and it is evident how much more easy it is to mount and adjust the seals, scrapers, etc. when both work rolls are outside and available, which is accomplished when the housing is opened. The lower immovable part I2 of the housing is coupled with the upper part 13 by a hinge I4 and a lock 15. Part 13 can be opened so as to occupy the position shown by dotted lines, so that both work rolls are on top and accessible. The scraper blades can be more conveniently adjusted and checked in their position at the work rolls. The maintenance of adjustment of this last-named element is of great consequence, since poorly or non-uniformly contacting scraper blades not only cannot perform their function properly, but also will damage the work rolls.

Precise locating means, to insure that the two halves of the housing will maintain their exact space relationship with respect to one another, must of course be provided. They may consist of pins, keys and the like, and can form part of or be used in conjunction with the clamping or tightening means. Such means may or may not exert a certain restraining action, helping to prevent a free flexion of the two beams at the joint, but such action would ordinarily be weaker than if the housing were all in one piece. A precisionbuilt hinge at one joint would possess both the locating feature and the necessary strength to take up the separating force. For higher precision, however, even the slightest play in the hinge 14 ing and joining means that perform the screwdown function at the same tim thus dispensing with the system used on this type of mill of turning the eccentric shafts which carry the casters.

Figure 12 shows one embodiment of this feature,

with one hinge I6 at one side of each column (and with its pintle extending parallel to the axes of the rolls) and a screw and nut element 11 at the other, so that with simultaneous operation of the two nuts, a parallel movement of the work rolls is always obtained.

The split housing arranged as in Figure 11 can also have a screw-down mechanism incorporated in the two joints I4 and 15 as by providing eccentric spindles, instead of straight pins. Said eccentrics, however, should preferalby be operated over a range of angles close to a horizontal plane. These eccentrics must also be both right or both left, and not symmetrical; and this arrangement permits a minimum axial displacement of the two work rolls throughout the screw-down range, a displacement which is not objectionable so long as it is small. The hinges arepreferably mounted above or below the plane of symmetry of the mill, so that they are not in the way of roll drive.

This arrangement makes itv possible either to depress both ends of the work rolls together, or

, one end independently of the other as is the case on conventional mills where the screw-downs of the two roll neck bearings ar independent of one another.

Figure 18 is a cross-section of still another mill embodiment to which our teachings are applicable. Mill beam 18 is encircled by a procession of small diameter rolls 19 extending all the way across the strip 3, either as single long rolls, or several parallel processions of shorter rolls disposed at spaced intervals across the width of the strip. The rolls may be loose or connected to chains (not shown), in which they arerotatably mounted. The work roll 5 is shown floating between the two intermediate rolls and 8 I, which are' backed by the housing 18 through the'procession of rolls 19. Suitable wear-resisting and properly shaped surfaces are, of course, provided on the beam. The procession of rolls 19, outside of the working zone, may be guided and returned to the working zone by any suitable means, such as an endless belt 82, led over pulleys 83. There may also be guides 84 and '85, and rotating parallel guide sprockets 86 and 81, preferably disposed near the working zone, and the purpose of which is to feed the rolls 19 in parallel relation to the intermediate rolls 88 and 8|, so that they can form bearings therefor against the beam.

As a means of obtaining screw-down, two wedges 88 and 89 are shown extending over the width of the strip 3 and interposed between the beam 18 and an upper, separate portion 18a forming the working zon support. For screwdown purposes, these wedges 88 and 89, are displaced symmetrically and laterally, by means not shown, whereby support 18a is raised or lowered. The corresponding gap in the path of the roll procession I is bridged because of the action of the ides 86 and 8I.

The wedges 8-8 and 89 can be displaced laterally, as indicated, but so as to assure their staying parallel with the roll 5 at all times, or they may be moved out of parallel, but still preferably symmetrically to each other (to the plane bisecting both work rolls) in which case a non-parallel screw-down movement can be obtained, In most cases, a strictly parallel screw-down is not only sufllcient but preferable.

The housing beam 18 is encircled by an oil case 90 closing at the work roll '5 with suitable passage restricting or oil-tight means like wipers 9| and 92. Lubricant is admitted into the work v zones as by holes 93, 94 and 95, and let'out at or close to the flexible wipers 9 I, 92 as above outlined.

Yet another mill embodiment to which our teachings are applicable is illustrated in Figures 16 and 17, which show an arrangement similar to Figures 13 and 14, but with oil film bearing members 93 and 94 provided for the intermediate rolls 95 and 96. These can be continuous along the length of the rolls, or discontinuous and spaced and distributed substantially over the width of the strip. The utilization of the whole axial space available on the intermediate rolls 95 and 96 isnot so vital in this instance, as with anti-friction bearings, because correctly designed oil-film bearings with pressure controlled oil film can withstand relatively high unit pressures. On the other.

hand, it is preferred to provide a mechanism for oscillating the bearings 93 and with either an axial (as by means of a cam shaft 91 between the bearing members, in the grooves of which cam shaft ears on the bearings engage as shown), or with a helical motion, in order to make the wear of the rolls more uniform and obtain an even polish and color of the strip as outlined. This applies in a still greater degree to work rolls and intermediate rolls made of the hard metallic car bide materials like "Carboloy and others. These of the strip at the roll bite, pick up the dirt and I impurities and the flow of lubricant, as described, and dispose of it, but in the long run, it is safer to have rolls made of a metal that will not be damaged by a small particle of dirt or a silver, if such roll also serves as part of an oil-fllm hearing. Hence, our preference for rolls made of such materials as Carboloy or similar hard substan es. Such rolls are economically possible as working or intermediate rolls in our mills because of their small diameter.

In Figure 19, we have shown a mill arrangement with which it is easier to remove lubricant from the surface of the strip as it leaves the mill, and to prevent undue loss of lubricant with the. strip. This is accomplished in an asymmetric mill. The small lower working roll is backed by two intermediate rolls as shown. These, in turn, rest upon one bottom series of casters 98 which are of large size, and which take the bulk of the roll-separating pressure. Two side series 99 and I 00 of smaller casters maintain the position of the intermediate rolls on the surface of the casters 98. ,They withstand relatively small side components of the roll-separating pressure. Yet

the casters 99 and I00 are of such size as to reach above the top of the work roll. Hence, the strip 3 is deflected upwardly at each side of the lower working roll. The top working roll I0! is of larger diameter than the lower working roll. It may,

indeed, be a conventional roll supported in bear- 16 l ings at necks at each end or, as shown, it can be supported by sets of casters I02 and I03 in the upper mill beam 8.

The provision and circulation of lubricant inthe mill of Figure 19 may be. that hereinabove described; but it will be noted that because of the deflection of the strip 3, it leaves the mill housing between beams I and 2 in upwardly slanting throats. .Thelubricant is removed from the mill through these throats, as hereinabove described, but by reason of the angles of the strip as it enters and leaves the mill, less of it tends to cling to the strip, and the provision of simple strip wipers is usually suillcient to leave the strip in a'iairly clean condition.

Another advantage of the type of mill shown in Figure 19 is economy in the number and size of casters because the horizontal components of roll pressure are small in proportion.

An advantageous modification of a simple type of mill with staggered or intermeshed casters is illustrated in Figure 20. Here the small work roll rests on two intermediate rolls which are primarily backed by caster series indicated at I04 and I05. A smaller series of casters Ill maintains the position of the intermediate rolls on the surfaces of casters I04 and I05; but the arrangement is such that the greater part of the roll-separating forces is sustained by casters I" and I05. The staggered arrangement illustrated permits us to bring the centers closer together.

Hence, we can, in such a mill, support working 'rolls as small as l-inch in diameter, with but one series of intermediate rolls, directly from casters which are no larger than 9 inches in diameter. The staggered arrangement also permits us to achieve a mill in which the percentage of horizontal roll pressure components is diminished, and this reduces the total bearing capacity required.

In connection with all of the mills described herein, where we have illustrated only the lower half of the mill mechanism, it will be understood that the upper half will, in most instances, be similar to that illustrated, although other con structions may likewise be employed. Any of the mills herein illustrated may be of a type in which the work piece moves always in one direction; but in most instances, we have described arrangements applicable to reversing mills.

Control of the flow of lubricant to produce jets having an enhanced velocity and, therefore, an enhanced flushing action, is not confined to mechanisms located at or near the working rolls.

By way of example, in Figure 21, we have illustrated a blade i0! located in the throat of the mill on the entering side, and adapted to confine the lubricant in such a way as to form a jet thereof between the blade and the strip as the lubricant moves out through the throat. The purpose of this jet is to flush the surface of the strip under pressure to remove small particles, slivers and sludge therefrom. Such means will, of course, be used on both sides of the strip and may be used on both sides of the mill in a reversing mill. The blades I01 are preferably of springy material for the production of an action such as that described in connection with Figure 9. They may be mounted on the mill housing or beam directly as shown, or they may be mounted on tunnel-forming members, such as the members 31 of Figure 1. They may be employed either alone or with other jet-forming members, such as those illustrated in Figures 8 and 9.

It will be evident that in the embodiments herein disclosed, the lubricant leaves the hollow of the mill housing through the mill throats; but instead of providing tunnel-forming members 31 as in Figure l,' throat liners may be formed, mounted in the throats, and sealed thereto, and bearing on their inner ends wiper or jet control blades, such as those illustrated in Figures 8 and 9.

It may be pointed out that in the long run, mill maintenance is a matter of probabilities and statistics. Considering lubrication, to which this application is primarily addressed, it is our object first to produce the mill bearings themselves, and we have disclosed various means of accomplishing this by providing either for the separate lubrication of these bearings or by supplying the general coolant-lubricant to these hearings first. With doctor blades or other lubricant control elements, including the hollow casings described in connection with Figures 13 and 14, we are next able to maintain in the hollow of the mill housing a bath of lubricant which can and does act as a coolant; and we are enabled to control the flow of this coolant in such a way as to prevent inequalities of temperature in the mill. Yet, should the doctor blades or equivalent mechanisms for any reason fail,

the lubrication of the mill bearings is not imrestricting the egress of lubricant from said space and means for withdrawing lubricant from said mill substantially at the level of the work piece therein.

2. The structure claimed in claim 1 in which the means for maintaining the bath of lubricant comprises baiile means forming restricted passageways for lubricant.

3. The structure claimed in claim 1 in which the means for maintaining the bath of lubricant comprises baflle means forming restricted passageways for lubricant, said baffle means acting in part at least against the work piece, and in which the lubricant is withdrawn from said bath through at least one of said throats.

4. The structure claimed in claim 1 in which the means for maintaining the bath of lubricant comprises bailie means forming restricted paspaired. So long as the doctor blades or similar flow-control instrumentalities perform their function, however, not only is cooling properly attained, but foreign matters are flushed from the mill in such a way as not to come into contact with any of the vital parts thereof including both the bearings and the working piece. We have not illustrated means outside the mill for producing circulation of the coolant or lubricant, or means for filtering or otherwise cleaning it, or means for cooling or otherwise independently controlling its temperature. Any suitable means may be employed for these purposes; and it will be within the skill of the worker in the art to efiect accurately balanced cooling not only by temperature control means, but also by control and variation of the rate of flow of temperature controlled coolant or lubricant.

Modifications may be made in our invention without departing from the spirit of it. Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. In a rolling mill characterized by work rolls,

beams for hearing the ultimate roll separating force and extending axially of the work rolls, passageways between the beams at each side of the mill forming throats through which the work piece enters and leaves the mill, and means for transmitting tlfi roll separating force from the work rolls to the beams, said means including bearings for force transmitting members supported by said beams, and means in connection with saidbeams for enclosing a space within said mill and between said beams, which space contains said working rolls and other operating members and is substantially closed except for said throats, a lubricating system including means for delivering lubricant separately and simultaneously to said bearings, means for delivering said lubricant from said hearings to the space between said beams to form a bath of lubricant therein in which lubricant travels toward the work piece from both sides thereof, means for maintaining said bath of lubricant by sageways for lubricant, said baflle means comprising members extending across the space within which said operating elements are located in the direction of the length of said beams and forming prolongations of said throats approaching the working rolls, and means supported by said last mentioned means in at least partial contact with said working rolls to restrict the flow of lubricant.

5. The structure claimed in claim 1 in which the means for maintaining the bath of lubricant comprises baffie means forming restricted passageways for lubricant, said baflle means comprising members extending across the space within which said operating elements are located in the direction of the length of said beams and formin prolongations of said throats approaching the working rolls, and means supported by said last mentioned means in at least partial contact with said working rolls to restrict the flow of lubricant, said last mentioned means operating to produce jets of lubricant substantially directed into the bite of the working rolls whereby to flush away extraneous particles of matter.

6. In a mill characterized on one side of the work piece by a hollow load sustaining beam. a work roll and means including elements having bearings for transmitting the rolling force from the work roll to the beam along the length of the work roll, a lubricating system comprising means for furnishing lubricant simultaneously to all bearing members, means for directing said lubricant thence to the hollow interior of said beam, means for maintaining a bath of lubricant in said hollow interior, and restrictive means for the egress of lubricant from said bath, said means being located substantially adjacent said work roll.

'7. In a mill characterized on one side of the work piece by a hollow load sustaining beam, a work roll and means including elements having bearings for transmitting the rolling force from the work roll to the beam along the length of the work roll, a lubricating system comprising means for furnishing lubricant simultaneously to all bearing members, means for directing said lubricant thence to the hollow interior of said beam, means for maintaining a bath of lubricant in said hollow interior, and restrictive means for the egress of lubricant from said bath, said means being located substantially adjacent said work roll, said means comprising baffle means substantially closing the hollow interior of said beam, said baflle means being in the form of a hollow casing with means for the egress of lubricant,

19 and means on said baflle means for effecting a sealing action against said work roll.

8. In a mill characterized on one side of the work piece by a hollow load sustaining beam, 21 work roll and means including elements having bearings for transmitting the rolling force from the work roll to the beam along the length of the work roll, a lubricating system comprising means for furnishing lubricant simultaneously to all bearing members, means for directing said lubricant thence to the hollow interior of said beam. means for maintaining a bath of lubricant in said hollow interior, and restrictive means for the egress of lubricant from said bath, said means being located substantially adjacent said work roll, and comprising doctor blades as part of said baflle means and means for forming jets of lubricant directed against said work roll.

9. In a mill of the character described comprising hollow load sustaining beams Separated at each side by a narrow throat through which a work piece passes substantially dividing the hollow within the beams into two parts, work rolls in each of said parts and supporting'means therefor including bearings whereby the work roll separating force is transmitted to said beams, means for maintaining a bath of fluid within the hollow interior of said mill comprising means for supplying fluid simultaneously to the hollow portions on each side of said work piece at a point remote therefrom and means for withdrawing lubricant from both parts of said hollow interior substantially at the level of said work piece, whereby the fluid is caused to move in said hollow interior parts continuously toward said work piece from both sides and whereby movement of said fluid in directions parallel to the axes of said work rolls is minimized.

10. In a mill of the character described, means for maintaining a bath of fluid in the hollow interior of a rigid beam containing a work roll for operating upon a work piece and rotary mechanical elements for backing said work roll on said beam, said means including lubricant delivery means opening to the hollow interior of said beam at least one point remote from said work roll, means sealing all said hollow interior except for a space adjacent said work roll and means thereon approaching said work roll so closely as to provide a restricted passageway for fluid thereat close to the line along which said work roll contacts said work piece whereby a bath of fluid is maintained in the hollow of said beam, having its exit confined to a line adjacent said work piece, said work roll having the greater part of its bulk submerged in said bath of fluid.

11. In a mill of the character described in which a work roll and rotary elements for backing said work roll on a beam are contained in the hollow interior of a rigid beam and are maintained in a fluid bath, exit means for said fluid bath comprising a doctor blade contacting said work roll along a line closely adjacent the line along which said work roll contacts a work piece, and a support for said blade, said support acting in part as a closure element for the hollow interior of said beam and having passageways formed therein to direct jets of fluid beyond said doctor blade and substantially in the plane thereof toward the line of contact between said working roll and a work piece.

12. In a mill of the character described in which a work roll and other operating elements are maintained in a bath of fluid in the hollow interior of a beam, means for isolating said bath comprising members attached to said beam and approaching said work roll closely enough to con fine egress of fluid from said bath to relatively narrow orifices adjacent said work roll whereby said fluid bath can be maintained under elevated pressure.

13. In a mill of the character described wherein a work roll and rotative elements for backing said work roll against a beam are maintained in a bath of fluid in the hollow interior of a rigid beam, rigid means approaching said work roll from an edge of said beam without contacting said work roll for confining said bath, and flexible means thereon for effecting a seal against said work roll.

14. In a mill of the character described wherein a work roll and other operating elements are maintained in'a bath of fluid in the hollow interior of a beam, means approaching said work roll for confining said bath and flexible means thereon for effecting a seal against said work roll, said last mentioned means comprising a double-bladed seal having an arcuate portion mounted in an arcuate recess in said baflle means whereby said double-bladed sealing means can pivot and follow movements of said work roll.

15. In a mill of the character described wherein a work roll and rotative operating elements for backing said roll against a beam are maintained in a bath of fluid in the hollow interior of a beam, means for maintaining said bath under elevated pressure comprising baflie means approaching but not contacting said work roll and a flexible doctor on at least one of said baflle means, contacting said work roll resiliently along a line adjacent the engagement of said work roll with a work piece and adapted to be separated from said work roll to form a restricted path for egress of said fluid substantially at said work piece by the action of the pressure of said fluid.

16. In a mill of the character described wherein a work roll and other operating elements including bearings are maintained in a bath of fluid in the hollow interior of a beam, means for producing a circulating bath of fluid in said'hollow interior and means for isolating said bath of fluid from the working surface of said work roll whereby a rolling lubricant of another character may be employed on a work piece.

17. In a mill of the character described wherein a work roll and other operating elements including bearings are maintained in a bath of fluid in the hollow interior of a beam, means for producing a circulating bath of fluid in said hollow interior and means for isolating said bath of fluid from the working surface of said work roll whereby a rolling lubricant of another character may be employed on a work piece, and further means for isolating said fluid bath from said bearings.

18. In a mill of the character described wherein a work roll and other operating elements including casters having bearings on shafts are maintained in a bath of fluid in the hollow inte- I rior of a beam, means for maintaining said bath of fluid in such manner that it can be circulated, means for isolating said bath of fluid from said bearings and means for separately lubricating said bearings comprising means for conducting lubricant to and withdrawing lubricant from said bearings through separate passageways in said shafts.

19. In a mill of the character described where in a work roll and other operating elements including casters mounted in bearings on shafts are maintained in a bath of fluid in the hollow interior of a beam, and in which said bearings are packed with grease, sealing means for isolating said bearings fromsaid fluid bath, means for delivering fluid on its way to said bath to said casters whereby to cool them, and means for withdrawing fluid from said bath in such manner as to maintain said bath in continuous and uniform motion as respects the extent of said work roll and said operating members.

20. In a mill of the character described wherein a work roll and other operating elements including casters mounted in bearings on shafts are maintained in a bath of fluid in the hollow interior of a beam, and in which said bearings are packed with grease, sealing means for isolating said bearings from said fluid bath, means for delivering fluid on its way to said bath to said casters whereby to cool them, and means for withdrawing fluid from said bath in such manner as to maintain said bath in continuous and uniform motion as respects the extent of said work roll and said operating members, including means for circulating fluid through said shafts to cool them.

21. A process of lubricating a mill of the character described wherein work rolls and other mill operating elements including bearings are located at each side of a work piece-in the hollow interiors of beams, which comprises causing the work piece to form a separating diaphragm between said hollow interiors, separately supplying fluid to the separated hollow interiors and withdrawing said fluid substantially in the plane of the work piece, and including the step of first supplying said fluid to said bearings and thence to the hollow interiors of said beams While maintaining baths of fiuid filling said hollow interiors by restricting the outlet of fluid therefrom.

22. A process of lubricating a mill of the character described wherein work rolls and other mill operating elements including bearings are located at each side of a work piece in the hollow interiors of beams, which comprises causing the work piece to form a separating diaphragm between said hollow interiors, separately supplying fluid to the separated hollow interiors and withdrawing said fluid substantially in the plane of the Work piece, and including the step of first supplying said fluid to said bearings and thence to the hollow interiors of said beams while maintaining baths of fluid filling said hollow interiors by restricting the outlet of fluid therefrom, and confining the egress of fluid from said baths to positions adjacent said work rolls.

23. In a mill wherein a work roll is supported axially on a beam by rotating pressure transmitting elements including oil film bearings, bearing elements mounted in said beam, force transmitting elements mounted in said bearing elements, means for supplying lubricant under pressure to said bearing elements and means for oscillating said bearing elements for the maintenance of oil films.

24. In a mill wherein a work 'roll is supported axially on a beam by rotating pressure transmitting elements including oil film bearings, bearing elements mounted in said beam, force transmitting elements mounted in said bearing elements, means for supplying lubricant under pressure to said bearing elements and means for oscillating said bearing elements for the maintenance of oil films, said last mentioned means comprising a movable cam shaft and members on said bearing elements engaging said shaft.

25. In a mill of asymmetric character a hollow beam, a work roll extending axially of said beam, means for supporting said work roll comprising casters mounted on a shaft supported by said beam, means for maintaining the position of the work roll with respect to said casters, said last mentioned means comprising casters 0! such diameter as to enforce a path of travel of a work piece to and from said work roll along and from which it is removed at an angle to the horizontal whereby drainage of the lubricant from the strip is facilitated.

26. In a rolling mill a beam, a work roll, supporting means for said work roll having hearings on said beam, said bearings comprising a procession of bearing rolls surrounding said beam, means for confining the path of travel of said bearing rolls and a casing surrounding the entire aforementioned structure and within which a bath of lubricant canbe maintained, said casing having parts approaching said work roll.

27. In a rolling mill a beam, a work roll, supporting means for said work roll having bearings on said beam, said bearings comprising a procession of bearing rolls surrounding said beam, means for confining the path of travel of said bearing rolls and a casing surrounding the entire aforementioned structure and within which a bath of lubricant can be maintained, said casing having parts approaching said work roll, said beam being formed in two parts with movable wedges for screw-down purposes located between said parts. i

TADEUSZ SENDZIMIR. JOHN E. ECKERT.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 977,725 Gautschi Dec. 6, 1910 1,519,657 Biggert Dec. 16, 1924 1,614,423 Coe Jan. 11, 1927 1,994,691 Dahl et al Mar. 19, 1935 2,056,433 Matthews Oct. 6, 1936 2,069,496 Kessler Feb. 2, 1937 2,085,449 Rohn June 29, 1937 2,150,340 Rohn Mar. 14, 1939 2,165,266 Hudson et al July 11, 1939 2,237,794 Sendzimir Apr. 8, 1941 2,243,010 Iversen May 20, 1941 2,279,347 Simons Apr. 14, 1942 FOREIGN PATENTS Number Country Date 291,323 Great Britain May 31, 1928 423,664 Great Britain Jan. 25, 1935 523,777 Great Britain July 23, 1940 

